• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.520-526
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• 2017

Carnosine was recently reported to protect against the DNA damage induced by oxidative stress. In this study, we investigated the protective effect of eel Anguilla japonica carnosine extracts prepared using different methods (heat treatment extracts, HTEs; ion exchange chromatography, IEC; ultrafiltration permeation, UFP) on leukocyte DNA damage using the comet assay. Human leukocytes were incubated with extracts of eel carnosine at concentrations (of 10, 50, $100{\mu}g/mL$), and then subjected to an oxidative stimulus [$200{\mu}M$ hydrogen peroxide ($H_2O_2$)]. Pretreatment of the cells for 30 min with carnosine significantly reduced the genotoxicity of $H_2O_2$ measured as DNA strand breaks. The protective effects of the three types of extract (HTE, IEC, and UFP) increased with concentration. At the highest concentration (100 g/mL). there were no statistical differences in oxidative damage between each extract treatment and PBS-treated negative controls. When leukocytes were incubated with carnosine for 30 min after exposure to $H_2O_2$. the protective ability of each extract changed. Therefore, eel carnosine inhibits the $H_2O_2$ induced damage to cellular DNA in human leukocytes, supporting the protective effect of this compound against oxidative damage.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.619-625
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• 2017

In this study, the formation of hydroxyl radical and decomposition characteristics of bisphenol A (BPA) was investigated by quantifying hydrogen peroxide formed as a reaction by-product during the formation stage of hydroperoxyl radical. The direct oxidation reaction by ozone only decomposed BPA just like the Criegee mechanism under the condition where radical chain reactions did not occur. Non-selective oxidation reactions occurred under the conditions of pH 6.5 and 9.5 where radical chain reactions do occur, confirming indirectly the formation of hydroxyl radical. The decomposition efficiency of BPA by the added catalysts appeared in the order of $O_3$/PAC ${\geq}$ $O_3/H_2O_2$ > $O_3$/high pH > $O_3$ alone. 0.03~0.08 mM of hydrogen peroxide were continuously measured during the oxidation reactions of ozone/catalyst processes. In the case of $O_3$/high pH process, BPA was completely decomposed in 50 min of the oxidation reaction, but reaction intermediates formed by oxidation reaction were not oxidized sufficiently with 29% of the removal ratio for total organic carbon (TOC, selective oxidation reaction). In the case of $O_3/H_2O_2$ and $O_3$/PAC processes, BPA was completely decomposed in 40 min of the oxidation reaction, and reaction intermediates formed by the oxidation reaction were oxidized with 57% and 66% of removal ratios for TOC, respectively (non-selective oxidation reactions).

• Journal of Environmental Health Sciences
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• v.23 no.3
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• pp.121-129
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• 1997

This study was performed to delineate the removal phenol in solutions using of ozone, ozone/$H_2O_2$ and ozone/GAC. The disinfection by-product of phenol by ozonation, hydroquinone, was analyzed and it's control process was investigated. The followings are the conclusions that were derived from this study. 1. The removal efficiency of phenol by ozonation was 58.37%, 48.34%, 42.15%, and 35.41% which the initial concentration of phenol was 5 mg/l, 10 mg/l, 15 mg/l, and 20 mg/l, respectively. 2. The removal efficiency of phenol by ozonation was 42.95% at pH 4.0 and 69.39% at pH 10, respectively. The removal efficiencies were gradually increased, as pH values were increased. 3. With the ozone/$H_2O_2$ combined system, the removal efficiency of phenol was 72.87%. It showed a more complete degradation of phenol with ozone/$H_2O_2$ compared with ozone alone. 4. When ozonation was followed by filtration on GAC, phenol was completely removed. 5. Oxidation, if carried to completion, truly destroys the organic compounds, converting them to carbon dioxide. Unless reaction completely processed, disinfection by-products would be produced. To remove them, ozone/GAC treatment was used. The results showed that disinfection by-product of phenol by ozonation, hydroquinone, was completely removed. These results suggested that ozone/GAC should also be an appropriate way to remove phenol and its by-product.

• The Plant Pathology Journal
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• v.29 no.4
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• pp.386-396
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• 2013

Reactive oxygen species (ROS) generation in tomato plants by Ralstonia solanacearum infection and the role of hydrogen peroxide ($H_2O_2$) and nitric oxide in tomato bacterial wilt control were demonstrated. During disease development of tomato bacterial wilt, accumulation of superoxide anion ($O_2{^-}$) and $H_2O_2$ was observed and lipid peroxidation also occurred in the tomato leaf tissues. High doses of $H_2O_2$ and sodium nitroprusside (SNP) nitric oxide donor showed phytotoxicity to detached tomato leaves 1 day after petiole feeding showing reduced fresh weight. Both $H_2O_2$ and SNP have in vitro antibacterial activities against R. solanacearum in a dose-dependent manner, as well as plant protection in detached tomato leaves against bacterial wilt by $10^6$ and $10^7$ cfu/ml of R. solanacearum. $H_2O_2$- and SNP-mediated protection was also evaluated in pots using soil-drench treatment with the bacterial inoculation, and relative 'area under the disease progressive curve (AUDPC)' was calculated to compare disease protection by $H_2O_2$ and/or SNP with untreated control. Neither $H_2O_2$ nor SNP protect the tomato seedlings from the bacterial wilt, but $H_2O_2$ + SNP mixture significantly decreased disease severity with reduced relative AUDPC. These results suggest that $H_2O_2$ and SNP could be used together to control bacterial wilt in tomato plants as bactericidal agents.

• Microbiology and Biotechnology Letters
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• v.5 no.3
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• pp.113-118
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• 1977

Into the precontaminated farm milk hydrogen peroxide ($H_2O$$_2$) was added at the concentrations ranging from 0.01％ to 0.05％ and kept at 3$0^{\circ}C$ for 16 hours with periodical determinations for viable counts, residual $H_2O$$_2$, and lactic acid. Under the tested conditions the initial level of contaminated bacteria could be arrested from growing at least for 8, 12, and 16 hours by treating the milk with 0.01, 0.02. and 0.03 per cent of $H_2O$$_2$, respectively. Furthermore, when the $H_2O$$_2$concentrations ware limited within the level of 0.03 Per cent the added $H_2O$$_2$was completely decomposed within 12 hours without the aid of external catalase and the decomposition time decreased in parallel with the $H_2O$$_2$ concentrations. A safer use of $H_2O$$_2$for preserving farm milk temporarily by limiting its concentration has been discussed.

• Journal of Soil and Groundwater Environment
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• v.6 no.1
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• pp.3-12
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• 2001

During ozonation process, the hydroxyl radical generation rates were measured under different experimental conditions (ozone feed rate, nitrobenzene concentration, hydroxyl radical scavenger, pH, HO$_2$O$_2$/O$_3$ etc.) Nitrobenzene could be decomposed by hydroxyl radical rather than ozone only and nitrobenzene decomposition rate was expressed with functions of ozone and nitrobenzene concentration. The rate was decreased as the hydroxyl radical scavenger concentration was increased, and all results were followed pseudo first-order reaction. Using a competitive method, hydroxyl radical generation rate was measured with probe compound and scavenger. It was proportional to ozone concentration, and 0.24mo1 of hydroxyl radical was produced with 1mol of ozone. Under different pH conditions, hydroxyl radical generation rates were measured (pH 10.2 (0.91Ms$^{-1}$ ) > pH 7.3 (0.72Ms$^{-1}$ ) > pH 5.6 (0.67Ms$^{-1}$ ) > pH 3.4 (0.63Ms$^{-1}$ )) showing higher generation rate at high pH values. Addition of hydrogen peroxide promoted the generation rate of hydroxyl radical. Considering the results of pH experiments and addition of hydrogen peroxide experiments, the hydroxyl radical generation rate was 1.6 times higher in hydrogen peroxide solution than in high pH solution, indicating addition of hydrogen peroxide is better promoter to produce the hydroxyl radical in ozonation. These results could be applied to AOPs to remediate the contaminated wastewater and groundwater.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.327-334
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• 2020

Oxidative stress is common cause of neurodegenerative diseases. The purpose of this study is to investigate the in vitro free radical scavenging activity and protective effect of three Glycyrrhiza species including Glycyrrhiza uralensis, G. glabra, and a new variety of Glycyrrihza (Shinwongam, SW) against hydrogen peroxide-induced oxidative stress in C6 glial cells. In vitro assays, radical scavenging activities of G. uralensis, G. glabra, and SW against 2,2-diphenyl-1-picrylhydrazyl, ·OH, and O2- increased as concentration-dependent manner. In addition, the SW was found to contain the highest polyphenol and flavonoid contents. The treatment of H2O2 to C6 glial cell induced oxidative stress, whereas G. uralensis, G. glabra, and SW significantly increased the cell viability as dose-dependent manner. In particular, SW exerted stronger protective effect on H2O2-induced cytotoxicity, than G. uralensis and G. glabra. Furthermore, reactive oxygen species (ROS) formation was significantly elevated by H2O2 in C6 glial cells. However, treatments of G. uralensis, G. glabra, and SW decreased ROS formation. In addition, SW decreased pro-inflammatory related protein expression levels such as inducible nitric oxide synthase and cyclooxygenase-2, compared to H2O2-treated control group. These results indicated that G. uralensis and G. glavra, especially SW, may be useful for preventing from oxidative stress-induced neuronal damage by regulating inflammatory reaction.

• Applied Chemistry for Engineering
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• v.3 no.3
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• pp.471-481
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• 1992

This study is related to the reactivity of dioxygen bridged palladium complexes having amine ligands. New dloxygen bridged palladium complexes were prepared using superoxide ion(${O_2}^-$) as an oxygen source. The reactions of dioxygen palladium complexes prepared in the study were examined in order to clarify the nature of the coordinated dioxygen. Treatments of a solution of the dioxygen bridged palladium complexes in benzene by water, methanol, acetic acid gave hydrogen peroxide($H_2O_2$) and hydroxy, methoxy, acetoxy-bridged palladium complexes, respectively. The dioxygen bridged palladium complexes reacted with substitution phenols of salicylaldehyde, 8-hydroxyquinoline and active mothylenes of acetylacetone, dimethyl malonate to afford mononuclear complexes of palladium and hydrogen peroxide. Furthermore, she dioxygen bridged palladium complexes changed to acetonyl bridged palladium complex and hydrogen peroxide reacting with acetone. The results suggest that dioxygen is coordinated as peroxo (${O_2}^{2-}$) in the complexes and behaves as a strong base.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.513-520
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• 1994

Background: The pathogenesis of silicosis has been focused on the interaction between alveolar macrophages and silica particle. Although fibrosis in silicosis has been studied extensively, the mechanism is still not fully understood. There is increasing evidence that monokines and arachidonic acid metabolites macrophage are involved in pathogenesis of silicosis. Recently, it was reported that prostaglandin E2 produced from macrophage counteracts the stimulatory effects of other monokines on fibroblast proliferation or collagen production. Until now, it was remained uncertain by which mechanism silica particle may activate alveolar macrophage to an enhanced release of prostaglandin E2. Methods: In order to investigate the relationship between the activity of alveolar macrophage and the production of $PGE_2$ from activated alveolar macrophage, the authors measured hydrogen peroxide and $PGE_2$ from alveolar macrophages activated by silica in vitro and from alveolar macrophages in the silicotic nodules from rat. Experimental silicosis was induced by intratracheal infusion of silica($SiO_2$) suspended in saline(50 mg/ml) in Sprague-Dawley rats. Results: produced by 1) The silicotic nodules with fibrosis were seen from the sections of rat lung at 60 days after intratracheal injection with 50 mg aqueous suspension of silica(Fig. 1). 2) In vitro, silica caused the dose dependent increase of hydrogen peroxide(p<0.05, Fig. 2A) and $PGE_2$(p>0.05, Fig. 2B) release from alveolar macrophages. Alveolar macrophages from rat with silicotic nodules released more hydrogen peroxide and $PGE_2$ than those of control group(p<0.05, Fig. 3). Conclusion: These results suggest that silica particle could activate macrophage directly and enhanced the release of $PGE_2$ and hydrogen peroxide from the alveolar macrophage.

• Molecules and Cells
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• v.39 no.1
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• pp.46-52
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• 2016

It is increasingly apparent that nature evolved peroxiredoxins not only as $H_2O_2$ scavengers but also as highly sensitive $H_2O_2$ sensors and signal transducers. Here we ask whether the $H_2O_2$ sensing role of Prx can be exploited to develop probes that allow to monitor intracellular $H_2O_2$ levels with unprecedented sensitivity. Indeed, simple gel shift assays visualizing the oxidation of endogenous 2-Cys peroxiredoxins have already been used to detect subtle changes in intracellular $H_2O_2$ concentration. The challenge however is to create a genetically encoded probe that offers real-time measurements of $H_2O_2$ levels in intact cells via the Prx oxidation state. We discuss potential design strategies for Prx-based probes based on either the redoxsensitive fluorophore roGFP or the conformation-sensitive fluorophore cpYFP. Furthermore, we outline the structural and chemical complexities which need to be addressed when using Prx as a sensing moiety for $H_2O_2$ probes. We suggest experimental strategies to investigate the influence of these complexities on probe behavior. In doing so, we hope to stimulate the development of Prx-based probes which may spearhead the further study of cellular $H_2O_2$ homeostasis and Prx signaling.